The test at hand queried whether the kernel supports CMMA, but in
addition machine support is required.
Add a check whether the machine supports CMMA.
This fixes the test under G3 (z/VM, KVM).
Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
---
tools/testing/selftests/kvm/s390x/cmma_test.c | 20 +++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c
index 6d0751ea224b..1d73e78e8fa7 100644
--- a/tools/testing/selftests/kvm/s390x/cmma_test.c
+++ b/tools/testing/selftests/kvm/s390x/cmma_test.c
@@ -660,12 +660,32 @@ struct testdef {
{ "GET_CMMA_BITS: holes are skipped", test_get_skip_holes },
};
+/**
+ * The kernel may support CMMA, but the machine may not (i.e. if running as
+ * guest-3).
+ *
+ * In this case, the CMMA capabilities are all there, but the CMMA-related
+ * ioctls fail. To find out whether the machine supports CMMA, create a
+ * temporary VM and then query the CMMA feature of the VM.
+ */
+static int machine_has_cmma(void)
+{
+ struct kvm_vm *vm = create_vm();
+ int r;
+
+ r = !__kvm_has_device_attr(vm->fd, KVM_S390_VM_MEM_CTRL, KVM_S390_VM_MEM_ENABLE_CMMA);
+ kvm_vm_free(vm);
+
+ return r;
+}
+
int main(int argc, char *argv[])
{
int idx;
TEST_REQUIRE(kvm_has_cap(KVM_CAP_SYNC_REGS));
TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_CMMA_MIGRATION));
+ TEST_REQUIRE(machine_has_cmma());
ksft_print_header();
--
2.39.1
